DE 20 2007 004 475 U1 discloses a filter assembly in which a filter holder features at least one through-hole which serves to sealingly accommodate a filter element with an adapter collar.
For example foam made of polyurethanes (PU), also called PU foam, may be used as seal between housing or housing cover and filter element. Such foam made of polyurethanes, however, tends to relax after heat storage or due to exposure to high temperatures or temperature change.
In other words, the foam made of polyurethanes is force-free after heat storage, having lost elasticity. With filter elements frictionally engaged in the housing this is often the reason why greater critical movements between the individual parts occur with vibration excitation of the assembly from the parts housing with housing upper part, seal, and filter element. Such a vibration excitation can, for example, may occur during the operation of a motor vehicle into which the filter is installed.